Operative Dentistry - Best Practices

Glass Ionomers

(last modified August 5, 2014)

“Glass Ionomers” = glass ionomer cement (GIC) and resin-modified glass ionomers (RMGI)

Although they have excellent adhesion and fluoride release/recharging ability they are limited in usage by their relatively poor bulk mechanical properties, esthetics and durability. Although not all studies and systematic reviews have shown a caries inhibitive/remineralization effect from the placement of glass ionomers we think that when high risk caries sites/populations are considered the evidence is supportive of the caries-inhibiting effect, eg. orthodontic brackets, ART restorations, direct fillings in high risk for caries patients.


  • high caries risk sites and patients
  • GIC mainly limited to provisional restorations
  • GIC or RMGI as sealants for erupting teeth
  • RMGI used as final restorations (primarily limited to crown margin repair and root caries)
  • RMGIs material of first choice for root caries
  • RMGI used when performing open sandwich

Relative Contraindications:

  • Xerostomia
  • Acid exposure: acidic diets, GERD, bulimia
  • Heavy occlusal forces


  1. Department currently limits our selection of “fluoride-releasing materials” to those with water in their composition (as opposed to those that rely upon absorbed water subsequent to placment)
  2. Glass ionomers are more durable with butt joint margins and when placed with sufficient bulk/thickness; however, due consideration must be given to conservation of tooth structure and a minimally invasive surgical approach.